feat(av-live): openpos 3D + DINO reid + filter

Three improvements wired end-to-end:

1. Openpos 3D skeleton visible: Skeleton3DRenderer attached to a
   RealityKit AnchorEntity in BodyView, toggled by showSkeleton
   or vizMode==9. PoseOSCListener now parses /pose3d/count and
   /pose3d/kp (plus restored /face/* and /hand/* paths).

2. DINO re-id (dinov2_vits14, ~9 ms ANE forward):
   MeshRigger combines Hungarian IoU with cosine similarity over
   a per-pid embedding history (deque maxlen=10), weighted by
   MULTIHMR_REID_ALPHA (default 0.5). Falls back to pure IoU if
   DINO mlpackage absent or scipy missing. state.last_frame_rgb
   buffer added so the rigger can crop bbox regions for embedding.

3. PoseFilterChain on pose_world_landmarks:
   median (anti-spike) -> Kalman constant-velocity ->
   50 ms lookahead -> IK elbow/knee/ankle clamp. Configurable
   via POSE_FILTER env (default median+kalman+lookahead+ik).
   <2 ms per frame for typical 1-2 persons.

Tests: 5 new in test_dino_reid.py + 6 new in test_pose_filter.py,
all green. Live validated by user: skeleton spawns, mesh stays
stable.

launcher/AV-Live-Body/Sources/AVLiveBody/BodyView.swift

@@ -101,6 +101,15 @@ struct BodyView: NSViewRepresentable {
         context.coordinator.sceneRenderer = scene
         context.coordinator.mtkView = mtkView
         context.coordinator.skeletonOverlay = SkeletonOverlay(parent: bodyAnchor)
+        // Skeleton 3D RealityKit armature (33 spheres + 32 cylinders bones)
+        // driven by /pose3d/* OSC from MediaPipe pose_world_landmarks.
+        // Visible quand toggle showSkeleton ou vizMode==9 (openpos).
+        let skel3dAnchor = AnchorEntity(world: SIMD3<Float>(0, 0, -2.5))
+        arView.scene.addAnchor(skel3dAnchor)
+        let skel3d = Skeleton3DRenderer()
+        skel3d.attach(to: skel3dAnchor, listener: poseListener)
+        context.coordinator.skel3dAnchor = skel3dAnchor
+        context.coordinator.skel3d = skel3d
         context.coordinator.keyLight = key
         context.coordinator.fillLight = fill
         context.coordinator.rimLight = rim
@@ -162,6 +171,9 @@ struct BodyView: NSViewRepresentable {
         let skelVisible = settings.vizMode == 9 || settings.showSkeleton
         c.skeletonOverlay?.update(persons: poseListener.persons,
                                   visible: skelVisible)
+        // 3D RealityKit armature : show/hide root anchor in sync with
+        // the same skelVisible signal as the 2D overlay.
+        c.skel3dAnchor?.isEnabled = skelVisible
         // Pose -> scene uniforms : drive hands3d (mode 8) et openpos
         // (mode 9) avec la premiere personne detectee. Les wrists pilotent
         // hand_l/r ; pose_count alimente bg_fragment.
@@ -211,6 +223,8 @@ struct BodyView: NSViewRepresentable {
         var sceneRenderer: SceneRenderer?
         var mtkView: MTKView?
         var skeletonOverlay: SkeletonOverlay?
+        var skel3dAnchor: AnchorEntity?
+        var skel3d: Skeleton3DRenderer?
         var kbMonitor: Any?
 
         deinit {

launcher/AV-Live-Body/Sources/AVLiveBody/PoseOSCListener.swift

@@ -26,8 +26,39 @@ final class PoseOSCListener: ObservableObject {
         var seenAt: TimeInterval = 0
     }
 
+    /// MediaPipe pose_world_landmarks : 33 keypoints in meters, hip-rel.
+    /// MediaPipe convention : x=right, y=down, z=forward (away from cam).
+    struct Pose3DFrame: Equatable {
+        var pid: Int = -1
+        var kps: [SIMD4<Float>] = Array(repeating: .zero, count: 33)
+        var hasPoint: [Bool] = Array(repeating: false, count: 33)
+        var seenAt: TimeInterval = 0
+    }
+
+    /// 68 dlib-style facial landmarks (x,y normalises 0..1).
+    struct FaceFrame: Equatable {
+        var points: [SIMD2<Float>] = Array(repeating: .zero, count: 68)
+        var hasPoint: [Bool] = Array(repeating: false, count: 68)
+        var seenAt: TimeInterval = 0
+    }
+
+    /// 21 MediaPipe hand landmarks per detected hand.
+    struct HandFrame: Equatable {
+        var side: Int = 0
+        var points: [SIMD2<Float>] = Array(repeating: .zero, count: 21)
+        var hasPoint: [Bool] = Array(repeating: false, count: 21)
+        var seenAt: TimeInterval = 0
+    }
+
     @Published var persons: [Int: PoseFrame] = [:]
     @Published var count: Int = 0
+    @Published var body3d: [Int: Pose3DFrame] = [:]
+    @Published var body3dCount: Int = 0
+    @Published var faces: [Int: FaceFrame] = [:]
+    @Published var hands: [Int: HandFrame] = [:]
+    @Published var faceCount: Int = 0
+    @Published var handCountLeft: Int = 0
+    @Published var handCountRight: Int = 0
 
     private var listener: NWListener?
 
@@ -148,13 +179,77 @@ final class PoseOSCListener: ObservableObject {
             p.skeleton = skel
             p.seenAt = CFAbsoluteTimeGetCurrent()
             persons[Int(pid)] = p
+        case "/face/count":
+            if let n = args.first as? Int32 { faceCount = Int(n) }
+            if faceCount == 0 { faces.removeAll(keepingCapacity: true) }
+        case "/face/kp":
+            guard args.count >= 6,
+                  let pid = args[0] as? Int32,
+                  let slot = args[1] as? Int32,
+                  let x = args[2] as? Float,
+                  let y = args[3] as? Float else { return }
+            let s = Int(slot)
+            guard s >= 0 && s < 68 else { return }
+            var f = faces[Int(pid)] ?? FaceFrame()
+            f.points[s] = SIMD2(x, y)
+            f.hasPoint[s] = true
+            f.seenAt = CFAbsoluteTimeGetCurrent()
+            faces[Int(pid)] = f
+        case "/hand/count":
+            if args.count >= 2,
+               let l = args[0] as? Int32, let r = args[1] as? Int32 {
+                handCountLeft = Int(l)
+                handCountRight = Int(r)
+                if handCountLeft + handCountRight == 0 {
+                    hands.removeAll(keepingCapacity: true)
+                }
+            }
+        case "/hand/kp":
+            guard args.count >= 7,
+                  let pid = args[0] as? Int32,
+                  let side = args[1] as? Int32,
+                  let idx = args[2] as? Int32,
+                  let x = args[3] as? Float,
+                  let y = args[4] as? Float else { return }
+            let i = Int(idx)
+            guard i >= 0 && i < 21 else { return }
+            var h = hands[Int(pid)] ?? HandFrame()
+            h.side = Int(side)
+            h.points[i] = SIMD2(x, y)
+            h.hasPoint[i] = true
+            h.seenAt = CFAbsoluteTimeGetCurrent()
+            hands[Int(pid)] = h
+        case "/pose3d/count":
+            if let n = args.first as? Int32 {
+                body3dCount = Int(n)
+                if body3dCount == 0 {
+                    body3d.removeAll(keepingCapacity: true)
+                }
+            }
+        case "/pose3d/kp":
+            guard args.count >= 6,
+                  let pid = args[0] as? Int32,
+                  let idx = args[1] as? Int32,
+                  let x = args[2] as? Float,
+                  let y = args[3] as? Float,
+                  let z = args[4] as? Float,
+                  let c = args[5] as? Float else { return }
+            let i = Int(idx)
+            guard i >= 0 && i < 33 else { return }
+            var p = body3d[Int(pid)] ?? Pose3DFrame(pid: Int(pid))
+            p.pid = Int(pid)
+            p.kps[i] = SIMD4<Float>(x, y, z, c)
+            p.hasPoint[i] = true
+            p.seenAt = CFAbsoluteTimeGetCurrent()
+            body3d[Int(pid)] = p
         default:
             break
         }
-        // Garbage-collect persons non vues depuis > 2 s
+        // Garbage-collect persons + body3d non vus depuis > 2 s
         let now = CFAbsoluteTimeGetCurrent()
         persons = persons.filter { $0.value.seenAt == 0
                                    || now - $0.value.seenAt < 2.0 }
+        body3d = body3d.filter { now - $0.value.seenAt < 2.0 }
     }
 
     // MARK: - Minimal OSC parser